India has the capability to increase the range of its 3,000 km Agni-III missile by another 1,500 km, according to country's top defence scientist Dr M Natrajan.
"We are working on a drawing board to extend the range of the missile by another 1,500 km," Natrajan said on the sidelines of a Defence Research and Development Organisation award function in New Delhi.
He also said that DRDO scientists were working on a submarine launch missile.
Describing the weapon as a strategic missile, he said a lot of work has been done on the propulsion system and the container design of the missile.
The DRDO secretary said that the new missile could be ready in three to four years.
"It is not difficult. We are interested in the technology of such a missile," he said.
His comments come amidst reports that India has been working to develop a Sagarika missile capable of being launched from a submarine.
The missile would have the capability of carrying nuclear warheads and would make India only the fifth country after United States, United Kingdom, France, Russia and China to develop such a missile.
Though Natrajan did not elaborate on extending the range of the Agni-III missile, DRDO sources said defence scientists were working on adding another rocket booster to the missile to give it an extended range by next two years.
India succefully test-fired a 3,000-km Agni-III missile on April 12 this year.
Asked about delays and cost overruns in DRDO's crucial projects, Natrajan said, 'Delays were inherent in every project which was a technology demonstrator.'
He said it was a misnomer to call it a delay as such projects could not be time-bound.